Synopsis The de Havilland DHC-6-300 Twin Otter, serial number 724, was on a defence visual flight rules flight from Goose Bay to Davis Inlet, Newfoundland, with a crew of two on board. The flight encountered instrument meteorological conditions en route and continued to Davis Inlet in these conditions under the defence visual flight rules flight plan. The crew flew a non-precision instrument approach to the airport and, at minimums, executed a missed approach because the required visual references were not established. A second approach was attempted; on the inbound track, the aircraft struck the frozen surface of the Labrador Sea two nautical miles north-northeast of the airport. The first officer was fatally injured, and the captain sustained serious injuries. The aircraft was destroyed. Ce rapport est galement disponible en franais. 1.0 Factual Information 1.1 History of the Flight The flight was a pilot self-dispatched, non-scheduled cargo flight from Goose Bay to Davis Inlet, Newfoundland, and was operating as Speed Air 960 under a defence visual flight rules flight plan. Before the flight, the captain received weather information from the St. John's, Newfoundland, flight service station (FSS)(1) via telephone and fax. The aircraft departed for Davis Inlet at 0815 Atlantic standard time (AST).(2) The captain was the pilot flying (PF). During the first approach, the first officer (FO) had occasional visual glimpses of the snow on the surface. The captain descended the aircraft to the minimum descent altitude (MDA) of 1340 feet above sea level (asl). When the crew did not acquire the required visual references at the missed approach point, they executed a missed approach. On the second approach, the captain flew outbound from the beacon at 3000 feet asl until turning on the inbound track. It was decided that if visual contact of the surface was made at any time during the approach procedure, they would continue below the MDA in anticipation of the required visual references. The captain initiated a constant descent at approximately 1500 feet per minute with 10 degrees flap selected. The FO occasionally caught glimpses of the surface. At MDA, in whiteout conditions,(3) the captain continued the descent. In the final stages of the descent, the FO acquired visual ground contact; 16 seconds before impact, the captain also acquired visual ground contact. At 8 seconds before impact, the crew selected maximum propeller revolutions per minute. The aircraft struck the ice in controlled flight two nautical miles (nm) from the airport (see Appendix B). During both approaches, the aircraft encountered airframe icing. The crew selected wing de-ice, which functioned normally by removing the ice. 1.2 Injuries to Persons 1.3 Damage to Aircraft 1.4 Other Damage 1.5 Personnel Information 1.5.1 General The two pilots were trained in accordance with the operator's training program and existing regulations. Both had attended a crew resource management (CRM) course conducted by Transport Canada (TC) two weeks before the accident. 1.5.2 The Captain The captain had been hired by the company in September 1998 and had completed a successful pilot proficiency check flight with a TC inspector on 20 October 1998. Except for a few minor items, the inspector noted that the pilot completed a well-flown check flight. After completing a line indoctrination of four flights, the captain was released to line operations. There was no record of subsequent checking of the captain's performance by either the company or TC. The captain was the most senior and experienced pilot based at Goose Bay. 1.5.3 The First Officer The FO was hired on 02 November 1998 with approximately 400 total flying hours. This was his first job with a commercial air operator. He completed a successful pilot proficiency check on 18 November 1998. The TC inspector noted that he demonstrated acceptable proficiency for FO duties on the Twin Otter. 1.6 Aircraft Information 1.6.1 Additional Aircraft Data The Twin Otter is a turbine-powered, short take-off and landing aircraft specifically designed to operate from relatively short, rough-surfaced runways. The aircraft was certified to operate in icing conditions; however, it is considered susceptible to ice-contaminated-tailplane stall (ICTS) under certain conditions. Consequently, the aircraft manufacturer has published specific operating instructions to be followed when operating in icing conditions in order to avoid ICTS. These instructions specify that the flight crew ensure correct operation of the airframe de-icing system before extending wing flaps and that the wing flaps should not be set beyond 10 degrees while operating in icing conditions. The aircraft was equipped for instrument flight rules (IFR) flight. A radio altimeter was included in the aircraft equipment. After the accident, the radio altimeter was found set to 1300 feet, which coincided with the MDA. 1.6.2 Aircraft Loading The aircraft was loaded with cargo the night before the accident flight. On the morning of departure, passenger seats, apparently to be used for the return flight, were placed in the rear of the aircraft as cargo. The cargo's total weight entered in the journey logbook was 2739 pounds; cargo documents available only accounted for 2190 pounds. The only damage to the floor and side wall track, used to attach seats and/or cargo tie-down rings, was to the side wall track on the right side of the aircraft in the area where eight steel doors had been secured. The fact that the remainder of the floor and side wall track was undamaged, especially in the area where two 400-pound wood stoves had been placed in the aircraft, indicates that the remainder of the cargo had not been secured. Personnel at the Goose Bay base lacked appreciation for the importance of correct loading and securement practices. The pilot-in-command (PIC) did not ensure that the cargo was properly loaded and safely secured. TC included a finding to this effect in its post-accident regulatory audit. Refuelling records indicate that 2200 pounds of fuel was added to a calculated 320 pounds of fuel that was already on board the aircraft. This indicates the aircraft was fully fuelled with 2520 pounds of fuel. The journey logbook fuel on board entry shows a fuel weight of 2000 pounds for the accident flight. The aircraft operational empty weight was 7741 pounds. Adding the operational empty weight to the cargo's recorded weight (2739 pounds) and the calculated fuel load (2520 pounds), the total aircraft weight would have been 13 000 pounds. The maximum take-off weight for the Twin Otter is 12 500 pounds. The company operations manual specifies that a copy of the weight and balance is to be left at the departure point, if practical. The crew had completed an operational flight plan, a copy of which was left at Goose Bay; however, no copy of the weight and balance form was found with this paper work. It was determined that it was normal for crews not to leave a copy of the weight and balance form at the departure point. 1.6.3 Ground Proximity Warning System The occurrence aircraft had previously been fitted with a ground proximity warning system (GPWS); however, the system had been removed. Regulation only requires GPWS equipment to be installed in turbo-jet powered aircraft that are greater than 33 069 pounds maximum certified take-off weight and that have a type certificate authorizing the carriage of 10 or more passengers. 1.7 Meteorological Information 1.7.1 Area Forecast The area forecast issued by Environment Canada for the area including Davis Inlet on 19 March 1999 at 1130 UTC, valid from 1200 to 2400 UTC (0800 to 2000 AST), contained the following information: A quasi-stationary north-northeast, south-southwest upper trough was situated 30 nm west of Goose Bay. Within 180 miles west of the trough, the sky conditions were expected to be 1500 to 3000 feet overcast, with cloud layers up to 13 000 feet and high broken cloud. The visibility was expected to be from 3 to more than 6 statute miles (sm) in light snow. Scattered embedded convective-type cloud was also expected to reduce visibility to between 0.25 and 3 sm in moderate or light snow, ice pellets, and blowing snow. Frequent stratus precipitation ceilings at 200 to 1000 feet were also forecast. 1.7.2 Aerodrome Forecast An aerodrome forecast (TAF) was not available for Davis Inlet Airport. A TAF issued for Nain, Newfoundland, which is approximately 45 nm northwest of Davis Inlet, for 1100 to 2300 UTC (0700 to 1900 AST) forecast a ceiling of 1500 feet overcast, visibility of 5 sm in light and blowing snow, and surface winds from 330 degrees true at 20 gusting to 30 knots. The TAF for Goose Bay for 1000 to 1000 UTC (0600 to 0600 AST) predicted visual flight rules (VFR) conditions with temporary ceilings of 1000 feet overcast and visibility of one mile in light snow after 1600 UTC. 1.7.3 Weather Reports The aviation routine weather report (METAR) for Nain at 1300 UTC (0900 AST) reported a ceiling of 2000 feet overcast and visibility of 10 sm in light and drifting snow. The surface winds were 330 degrees magnetic at 20 gusting to 25 knots. Weather received by the crew from the St. John's FSS while en route was consistent with this METAR. METARs were not available for Davis Inlet; consequently, crews obtained actual weather information from local townspeople. The company had made arrangements several days before the accident to receive this information from a local resident; however, it could not be verified if weather for Davis was obtained before flight. It was determined that the aircraft was operating in instrument meteorological conditions and icing conditions during both instrument approaches. During the second approach, the crew requested the local weather and were informed that the ceiling was 150 to 200 feet. Another company aircraft conducted an approach and missed approach in the Davis Inlet area approximately one hour after the accident and subsequently diverted to Nain because the pilot did not see the landing area at MDA. The pilot of this aircraft encountered moderate, mixed icing conditions. 1.8 Aids to Navigation There is one instrument approach for Davis Inlet, the non-directional beacon (NDB) A. This approach is based on the Davis Inlet NDB, which is south of the runway's extended centreline. The published instrument procedure is a circling approach. The MDA is 1340 feet asl (1295 feet above ground level), and the published advisory visibility is 3 sm. The approach procedure is to the north-northeast of the airport and, for the most part, over the ocean. The missed approach point is at the NDB (see Appendix C). 1.9 Communications Communications between Speed Air 960 and Air Traffic Services were normal throughout the flight. Approximately 20 minutes before reaching Davis Inlet, the crew were in contact with company dispatch in St. John's via high frequency radio. Five minutes before arriving overhead the airport, the flight crew transmitted on the traffic advisory and the universal communications (UNICOM) frequencies their intentions to conduct the NDB A instrument approach at Davis Inlet. 1.10 Aerodrome Information Davis Inlet is 155 nm north-northeast of Goose Bay. The airport, operated and maintained by the Government of Newfoundland and Labrador, is a certified aerodrome adjacent to the community. The airport identifier is CCB4, and the reference elevation is 45 feet asl. Runway 14/32 is gravel surface 2500 feet long by 75 feet wide. It is the only runway and is parallel with and adjacent to the shoreline. 1.11 Flight Recorders The aircraft was equipped with a Loral cockpit voice recorder (CVR). This unit was recovered from the accident site and sent to the TSB Engineering Branch for analysis. It had recorded up to the point of impact; 32 minutes of good quality audio data were obtained. The aircraft was not equipped with a flight data recorder, nor was one required by regulation. 1.12 Wreckage and Impact Information The aircraft struck snow-covered ice on a heading of 222 degrees magnetic in a slightly nose-down, wings-level attitude. The wreckage trail was approximately 600 feet long by 180 feet wide: the nose landing gear was near the beginning of the trail; the instrument panel was at the end of the trail; and the fuselage, engines, left wing, empennage, and cargo were strewn along the trail between these points. The wreckage pattern observed was consistent with a controlled, shallow descent. During the break-up, the cockpit was destroyed, and all of the cabin-area cargo exited through the front of the aircraft. The absence of damage to load securing attachment points and the absence of load restraining devices indicated that the load had not been restrained. The electronic timer and the horizontal stabilizer distributor valve and pressure switch unit for the airframe de-icing system were removed and sent to the TSB Engineering Branch for examination. It was determined that these items were serviceable at the time of impact. The right wing remained attached to the aircraft. Measurements were taken of the flap position on this wing in relation to a reference point on the fuselage. Measurements were also taken of the positions of the control rods attached to this flap. The flaps on an in-service aircraft were set to these measurements, and a flap angle of 14 degrees was recorded. The normal operating flap selections are 10, 20, and 40 degrees; these selections are to correspond to actual flap angles of 10, 20, and 37.5 degrees. Possible explanations for the flap position reading of 14 degrees are as follows: the flaps were in transit beyond 10 degrees at impact; erroneous measurements resulting from impact-related fuselage deformation; the flap selector lever was not aligned with the 10-degree position mark (there are no detents); or rigging differences between the two aircraft. During both approaches, the only flap positions selected by the crew were up or 10 degrees. Consequently, it is unlikely that the flaps were past 10 degrees; the post-impact flap position probably corresponds to the 10 degrees selected by the crew. The discrepancy is due to impact effects, rigging differences, and/or selector position. 1.13 Medical Information There was no indication that incapacitation or physiological factors affected the crew's performance. 1.14 Fire 1.15 Survival Aspects At the time of the accident, an airport employee heard a loud bang. He alerted others, and a ground search was initiated by the community in the direction of the approach path. The wreckage site was found a short time later. Both crew members had been thrown from the aircraft; the FO had been fatally injured, and the captain had sustained serious injuries. The captain's injuries were treated at the site and at the community clinic by a local nurse until he could be evacuated. The aircraft's emergency locator transmitter (ELT) was rendered inoperative due to impact forces. However, this did not delay locating the aircraft because even if the ELT had activated, no equipment capable of homing in on the signal was available at Davis Inlet. 1.16 Tests and Research No tests or research were conducted. 1.17 Organizational and Management Information 1.17.1 General At the time of the accident, the company operated a diversified fleet of aircraft, including Twin Otter, Beechcraft King Air, Fairchild Metro, Piper Navajo, and Britten-Norman Islander aircraft. The Twin Otter and Metro III were operated as Interprovincial Airlines. The company's main base of operations was St. John's, and sub-bases were established in four cities: Halifax, Nova Scotia; Goose Bay, Newfoundland; Sault Ste. Marie, Ontario; and Vancouver, British Columbia. The company held an air operating certificate issued by TC authorizing the operation of the Twin Otter aircraft in commercial air service for passenger and cargo carriage under IFR and night VFR. The aircraft was operated under Canadian Aviation Regulation (CAR) 704, Commuter Operations, and was dispatched under a Type C dispatch system. Under this system, the PIC is authorized to self-dispatch a flight. 1.17.2 Management The company is privately owned. The operations manager and the director of maintenance report directly to the president, and the chief pilot reports directly to the operations manager. The chief pilot and the operations manager were directly involved with flight crew hiring and had hired the crew of the accident flight. The operations manager was responsible for ensuring that all flights were conducted in accordance with the company operations manual. 1.17.3 Goose Bay Operations The company Twin Otter operation was based in Goose Bay. The Goose Bay operation was not identified as a sub-base in the air operating certificate or the company operations manual, nor was it required to be by regulation. Goose Bay company personnel consisted of a base manager, pilots, and maintenance staff. One of the base manager's duties was loading aircraft; he had loaded the accident aircraft the night before the departure. On 02 February 1999, TC inspectors monitored the Twin Otter operation at Goose Bay. The monitoring consisted of one ramp check, which was conducted with the accident crew, and one in-flight inspection, which was conducted with two other Goose Bay pilots. No anomalies or deficiencies were identified. 1.18 Additional Information 1.18.1 Flight Planning An IFR flight plan requires that an aircraft carry sufficient fuel to proceed to destination and then to a suitable alternate airport, plus reserve fuel (approach and missed approach fuel plus 45 minutes at normal cruise). The weather data the captain had received before departure showed that alternate airports were available. However, he departed under VFR and, when instrument meteorological conditions were encountered en route, he continued under the VFR flight plan. CAR 602.115, Minimum Visual Meteorological Conditions for VFR Flight in Uncontrolled Airspace, states in part: during the day, flight visibility is not less than one mile, during the night, flight visibility is not less than three miles, and in either case, the distance of the aircraft from cloud is not less than 500 feet vertically and 2,000 feet horizontally; during the day, flight visibility is not less than two miles, except if otherwise authorized in an air operator certificate or a private operator certificate, during the night, flight visibility is not less than three miles, and in either case, the aircraft is operated clear of cloud; and . . . during the day, flight visibility is not less than two miles, except if otherwise authorized in an air operator certificate or a private operator certificate, during the night, flight visibility is not less than three miles, and in either case, the aircraft is operated clear of cloud; and . . . during the day, flight visibility is not less than two miles, except if otherwise authorized in an air operator certificate or a private operator certificate, during the night, flight visibility is not less than three miles, and in either case, the aircraft is operated clear of cloud; and . . . VFR flights should be planned to avoid encountering weather that is below the requirement for the flight. CAR 602.72 requires that pilots be familiar with the available weather information that is appropriate for the flight. However, regulations do not preclude a pilot from filing a VFR flight plan with weather conditions that are forecast or reported to be below VFR minimums. In this occurrence, the weather en route was forecast to be below the requirements for VFR. 1.18.2 Standard Operating Procedures CARs require that standard operating procedures (SOPs) be established and maintained for each aircraft type that will be flown with two or more pilots in a commercial operation. These procedures use the challenge-and-response method to ensure that important cockpit checks are conducted. SOPs were established and maintained by the Twin Otter aircraft operator. The company operations manual states that SOPs are a means of ensuring that ...a high level of safety is achieved through crew co-ordination in the handling of routine and emergency situations. They include standard calls through altitudes, when instrument approach procedures will be reviewed, etc. No deviation from the procedures is acceptable unless the PIC determines that the safety of the flight may be compromised. Some of the following Twin Otter SOPs were applicable to the occurrence flight: ATS instructions Approach in use Missed approach (including obstacle clearance) Flap setting Vref (confirm landing weight) ATS instructions Approach in use Missed approach (including obstacle clearance) Flap setting Vref (confirm landing weight) With respect to timing on Non-Precision Approaches, Holds, and Procedure Turns, the PF will request the PNF [pilot not flying] to start his time precisely at that instant by stating Start Time Now, at which time the PNF will start the clock for the specific manoeuvre. The approach check shall be initiated and the aircraft configured at approximately five miles from the airport facility. The PF calls for the Approach Checklist and the PNF actions the approach checklist, calls Approach Checklist Complete and Landing Checklist Next. Non-Precision Approach Procedure: Very few of the required SOP calls were made, and the approach briefing and the approach and landing checks were not conducted. Only one call through an altitude was made during the initial approach; no calls through altitudes were made on the second approach. There was no indication that the crew were aware of their altitude until shortly before the point of impact. 1.18.3 Crew Resource Management CRM training is a requirement for CAR 705 (airline) operations. Although CRM training is not required for CAR 704 (commuter) operations, both crew members had received this training from TC two weeks before the accident. The application of CRM concepts can improve crew performance through enhanced communication, problem solving, decision making, and workload management. The captain had significant overall flying experience and approximately 2500 hours on the Twin Otter. The FO had relatively little flying experience and very little experience on the Twin Otter. Studies have shown that inappropriate pairings of pilots (according to experience levels and personality traits) have been contributing factors in aircraft accidents.(4) The practice of CRM should reduce this risk. The captain frequently disregarded SOPs and either discouraged or ignored inputs and prompts from the FO on the conduct of the flight, indicating that important CRM concepts were not being applied. 1.18.4 Controlled Flight into Terrain Controlled flight into terrain (CFIT) accidents are accidents in which an aircraft, capable of being controlled and under the control of the crew, is flown into the ground, water, or obstacles with no prior awareness on the part of the crew of the impending collision. Although CFIT accidents occur in all phases of flight, most occur during the approach and landing phase of flight. A study by the Flight Safety Foundation Approach-and-Landing Accident Reduction (ALAR) Task Force identified causes of and contributing factors to CFIT accidents in approach and landing occurrences.(5) The most common causes and contributing factors are the following: Poor professional judgement: Not executing a missed approach in the absence of visual cues; Omission of action / inappropriate action: Omission of approach briefing or altitude call outs; failure to check the radio altimeter; failure to call out runway in sight / no contact at MDA; and omission of checklist items; Failure in CRM: Continuing an approach in adverse conditions; descent below MDA/DH [decision height] prior to acquiring visual cues in whiteout conditions; absence of standard call outs and briefings; and failure to recognize deviations from standard/approved procedures. Failures in CRM may be associated with complacency and overconfidence, high workloads, cultural influences, and a lack of risk assessment; and Lack of positional awareness: Lack of vertical position awareness resulting in CFIT. It should also be noted that 75 per cent of aircraft involved in the ALAR study were not equipped with a GPWS.